Speaker systems, such as the speaker systems mounted on aircraft and other vehicles, include one or more cone speakers powered by one or more amplifiers. Recent developments in the design of loudspeaker systems incorporate flat panel speakers as part of a vehicle loudspeaker system. An example of such a flat panel speaker system is described in U.S. application Ser. No. 13/929,073 filed Jun. 27, 2013, the contents of which are incorporated herein by reference. With such flat panel speakers, a portion of the panel defining a passenger cabin or other enclosure on a vehicle may be used as the diaphragm of a driver of the loudspeaker system. Because the mass of such flat panel speakers is many times greater than the mass of a conventional cone diaphragm that may be made of paper, plastic, lightweight composites or metal foil, a driver incorporating such a flat panel diaphragm may require an audio signal from an amplifier that is significantly more powerful than the audio signal required to drive a traditional cone speaker.
While employing larger and more powerful amplifiers may provide sufficiently powerful audio signals to such flat panel speakers, such larger and heavier amplifiers add weight to the vehicle, require more onboard electric power, and require extensive testing and certification. Accordingly, there is a need for a loudspeaker (driver or exciter) system that is sufficiently powerful to drive flat panel speakers, but does not require more power from relatively heavy amplifiers that also draw more power from the onboard power supply system.